We propose to study the magnetic moment and the magnetic layer profile in order to rule out the presence of magnetic dead layers at the interface in thin Fe films grown epitaxially on GaSb/AlSb/GaAs(001) and GaSb(001) substrates as a function of thickness using polarised neutron reflectometry (PNR). Our goal is to obtain information of the magnetic depth profile of Fe and the magnetic interface between Fe and high spin-orbit coupling (SOC) material GaSb. This information will help us to better understand the magnetic-transport measurement results and the magnetic properties obtained by conventional magnetometry on our structures.